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Post by faz on Apr 1, 2013 7:09:25 GMT
Looks like a great day was had by all - great work Terry  |
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Post by hedgemonkey on Apr 1, 2013 17:22:55 GMT
A day well spent by the look of it. How do you find the Night storage heater bricks work for you? For long term use would a single layer be any good do you think? Do you mortar the bricks to the celcon or bed them in sand.For my first cob I didn't mortar them and they always wobbled a bit.
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Post by cannyfradock on Apr 1, 2013 17:59:41 GMT
A day well spent by the look of it. How do you find the Night storage heater bricks work for you? For long term use would a single layer be any good do you think? Do you mortar the bricks to the celcon or bed them in sand.For my first cob I didn't mortar them and they always wobbled a bit. Don't know yet personally how the night storage fire-bricks will perform. They are designed to hold and reflect heat and the feedback from people who have used them on the forum has been very positive. I have every faith in them.(I have quite a bit of knowledge and personal experience in building Pompeii and clay ovens, but a lot of my knowledge has come from the guys who post on this forum so....I'm still learning)..... In answer to your question....The storage heater fire-bricks are 2" in depth...1 layer will be enough to work with a clay dome. The thermolite blocks (celcon) have been laid with normal mortar. This last clay oven build was built on a wooden base with a sheet of chipboard as the slab......I laid the blocks with neat uni-bond on top of the boards. (No heat should penetrate to the underside of an insulation block)......I laid the SH fire-bricks on the blocks with a stiff mix of flexible floor tile adhesive. I think this will work...if not, then the adhesive will turn powderish but still leave a level hearth.....time will tell. I wouldn't advise pure sand, but a mix of pure sand (not fine) and hydrated lime ....about 6:1 in ratio will firm the sand up and allow expansion to happen on the underside of the fire-bricks. The best mortar to lay the fire-brick hearth is the homebrew mix of sand, cement, lime and powdered fire-clay at a ratio of 4:1:1:1........I mix this into a paste and lay a bed of this mix with a 10mm knotched trowel. The fire-bricks can then be slightly tapped to leave an even hearth. Terry |
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Post by hedgemonkey on Apr 1, 2013 19:51:25 GMT
thanks Terry, I'll give the homebrew a try, what type of lime would you use?
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Post by cannyfradock on Apr 2, 2013 18:06:13 GMT
...hydrated lime. Available from most builders merchants or garden centers.
It won't hurt also to add cement at the same ratio of the lime...perhaps an 8:1:1 ..sand, lime cement mix. The lime will help give the mix a little "give" coping with the temperature changes and the cement will give the mix stability.
This mix will be best used "semi-dry" about half or 3/4 of an inch deep. Although fire-bricks or storage heater fire-bricks look very uniform, there are slight differences in each brick, so if you spread the dry mix with a level, then lay your bricks on top, you can then use a rubber mallet to tap the bricks level. Any bricks that have a corner sticking up can be ground down.....after the mix has set, with a 4" angle grinder using a masonry grinding disc.
Terry
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Post by cannyfradock on Aug 29, 2013 19:24:37 GMT
My next Clay/Cob oven building workshop is on the 28th September. I'm looking for a few more people to make up to 6 people for this course. More info on the course can be seen by clicking this link... www.celticwoodfiredovens.com/Clayovenbuildingcourses.html Forum members receive a 10% discount on course fees. Terry p.s....I hope the moderators don't delete my post or ban me for promoting this on the open forum  |
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Post by cannyfradock on Sept 29, 2013 10:52:24 GMT
"8th September course pics.... Puddling the clay...  Forming the cob balls around the sand form...  Nearly finished with the first layer...  Bit of artistic immpression on the outer coat from Jill...  Brian and Lillian.....  Can you guess what it is yet?...  Jill's first attempt.....not bad  Brial and Lil outside the workshop..  Everybody made pizzas and took some home with them. Left over dough at the end of the day was formed into loaves and baked in a hot wood-fired oven. Toooo hot ......They looked good, but that oven would have needed to cool it's massed heat for at least another hour before it was ready for bread. Everybody formed and slashed their own loaf ....and had a good laugh when the loaves were broken open...  Terry |
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Post by rockrocky on Sept 29, 2013 13:38:37 GMT
They all seemed to have a great clay out!
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